Historically, immigrants have integrated well into our society. It has sometimes taken a generation or two but, ultimately, if you went to a British school, watched British television and mixed with British people, you assimilated into our culture.
We have a number of problems with that now. Firstly, the amount coming in means that they can live in their own community, practise their own culture and speak their own language. Schooling, which is so important, in many cases adapts to their culture rather than trying to teach them ours. Finally, the internet means that they can seek entertainment and advice in their own culture and that confirms to their cultural norms.
The above isn’t that problematic if their native culture is peaceful and egalitarian. But, if it is religious and misogynistic, it can be a huge problem. And this problem is manifesting itself in the lived experiences reported by many on this thread.
Luxury belief is a really good term. I have many friends who are male, wealthy and send/sent their children to private schools in very wealthy areas of London. Their main contact with recent immigrants is either at work, where they are very well educated and cultured or who are doing domestic/building work for them, where, again, they are polite and respectful (obviously). It is incredibly easy for them to quote uncritically economic theory that says immigration is only a positive.